Distinguishing luminal breast cancer subtypes by Ki67, progesterone receptor or TP53 status provides prognostic information

Cells with high CD44 but low CD24 expression (CD44high/CD24−/low) and high aldehyde dehydrogenase activity (ALDHbr) are widely considered to be drivers of metastasis, therapy resistance and tumor recurrence in breast cancer. However, the role of the CD44high/CD24−/low and ALDHbr phenotypes in identifying tumorigenic cells in breast cancer remains controversial due to the discrepancy in their distribution and tumorigenic potential in intrinsic breast cancer subtypes. In this study, we analyzed the cells expressing these markers in six different breast cancer cell lines representing major breast cancer subtypes (T47D, MCF-7, BT-474, AU-565, Hs578T and MDA-MB-231). CD44high/CD24−/low, ALDHbr and CD44−/low/CD24−/low cell populations were isolated by flow cytometry and analyzed for hallmark stem cell characteristics of differentiation, migration, invasiveness and metastasis using in vitro and in vivo techniques. Our results demonstrate that the CD44−/low/CD24−/low cell population, which is enriched in luminal cell lines (T47D, MCF-7 and BT-474), possesses metastatic and tumorigenic properties. We also show that, contrary to previous claims, the expression of the ALDH1 isoform ALDH1A1 does not affect the tumorigenic potential of cell lines with high ALDH activity (BT-474 and AU-565). Further transcriptomic and clinical studies are needed to determine the potential of these markers as early diagnostic tools and treatment targets.

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BRIP1 overexpression is correlated with clinical features and survival outcome of luminal breast cancer subtypes

Endocrine Connections ◽

10.1530/ec-17-0173 ◽

2018 ◽

Vol 7 (1) ◽

pp. 65-77 ◽

Cited By ~ 6

Author(s):

Ishita Gupta ◽

Allal Ouhtit ◽

Adil Al-Ajmi ◽

Syed Gauhar A Rizvi ◽

Hamad Al-Riyami ◽

...

Keyword(s):

Breast Cancer ◽

Triple Negative ◽

Breast Cancer Subtypes ◽

Luminal Breast Cancer ◽

Dual Function ◽

Potential Candidate ◽

Cancer Subtypes ◽

Her2 Breast Cancer ◽

Potential Biomarker ◽

Tumor Stages

In Oman, breast cancer is most common, representing approximately more than 25% of all cancers in women. Relatively younger populations of patients (25–40 years) present surprisingly with an aggressive phenotype and advanced tumor stages. In this study, we investigated differential gene expressions in Luminal A, Luminal B, triple-negative and Her2+ breast cancer subtypes and compared data to benign tumor samples. We identified a potential candidate gene BRIP1, showing differential expression in the four breast cancer subtypes examined, suggesting that BRIP1 has the profile of a useful diagnostic marker, suitable for targeted therapeutic intervention. RT-qPCR and Western blotting analysis showed higher BRIP1 expression in luminal samples as compared to triple-negative subtype patient’s samples. We further screened BRIP1 for eventual mutations/SNPs/deletions by sequencing the entire coding region. Four previously identified polymorphisms were detected, one within the 5′-UTR region (c.141-64G > A) and three in the BRCA-binding domain (c.2755T > C, c.2647G > A and c.3411T > C). Kaplan–Meier analysis revealed that patients with overexpression of BRIP1 displayed a poor survival rate (P < 0.05). BRIP1 has a dual function of an oncogene and a tumor suppressor gene in addition to its role as a potential biomarker to predict survival and prognosis. Data obtained in this study suggest that BRIP1 can plausibly have an oncogenic role in sporadic cancers.

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